This handy overview lists the pros and cons of both routes of taking your book into print. Self-published and small-press authors have many decisions to make about production, publicity, and promotion, so finding this kind of information cuts through the chaos.
The author has also written an article comparing Smashwords and Draft2Digital here.
“A note before we begin: All of the sites request some of the same information, so you will need to have it handy. They will ask for your name, your address, your email address, the password(s) you want to use, and some very basic financial information: your Social Security number for US residents, and the routing number and account number for the bank where you want them to deposit your royalties. And okay, another note – each will have different requirements for
book covers, so make sure to read those on the respective sites.”